Method of and mixer block for feeding a stream of viscous material

ABSTRACT

A method of and mixer block for feeding a stream of viscous material into a mixer employing not rotating parts is disclosed. The mixer block has a cavity therein terminating in an outlet which feeds the raid mixer. A first inlet is provided into the cavity at a point displaced from the outlet end for introduction of a first viscous material while a second inlet is provided between the first inlet and the outlet to introduce the second viscous material into the interior of the flow of the first viscous material thereby presenting a coaxial stream of viscous material to the said mixer.

United States Patent 1 1 1 EJ'FLMS Phillips et al. 51 June 5, 1973 54] METHOD OF AND MIXER BLOCK FOR 3,677,522 7/1972 Hargash ..259 4 FEEDING A STREAM OF VISCOUS 21:32; MATERIAL 2:802:64s 8/1957 Christensen ..259 4 Inventors: Henry A. Phillips, 1340 New Brunswick Avenue, Piscataway; Reynold E. Minnich, i309 Washington Valley Road, Martinsville, both of NJ.

Filed: Nov. 3, 1971 Appl. No.: 195,213

Primary ExaminerRobert W. Jenkins Attorney- Lawrence l. Lerner, Sidney David and Joseph S. Littenberg [57] ABSTRACT A method of and mixer block for feeding a stream of viscous material into a mixer employing not rotating parts is disclosed. The mixer block has a cavity therein terminating in an outlet which feeds the raid mixer. A first inlet is provided into the cavity at a point displaced from the outlet end for introduction of a first viscous material while a second inlet is provided between the first inlet and the outlet to introduce the second viscous material into the interior of the flow of the first viscous material thereby presenting a coaxial stream of viscous material to the said mixer.

9 Claims, 3 Drawing Figures METHOD OF AND MIXER BLOCK FOR FEEDING A STREAM OF VISCOUS MATERIAL FIELD OF THE INVENTION This invention relates to metering and mixing devices and machines and the like, and particularly to a method and apparatus for feeding of materials to be mixed to such machines.

BACKGROUND OF THE INVENTION Mixing devices and the like are well known as evidenced by U.S. Pat. No. 3,286,992 granted Nov. 22, 1966 to C. D. Armeniades et al. The patented device is a static type mixer, that is, a mixer which does not employ any rotating parts. Such a mixer generally receives the materials to be mixed at one end and delivers it out of the other end after it has gone through a number of mixing stages.

Though the patented device has proved to be quite efficient and successful, it has certain drawbacks. Perhaps the most serious drawback is due to the fact that unless the materials to be mixed are fed to the static mixer in the right proportions over short time intervals, a completely homogenous mass is not formed at the outlet end. It will be appreciated that the mixing takes place as the materials are moving from the inlet to the outlet and therefore there is no possibility of correcting the ratio of materials to be mixed over a time interval as is possible with a rotating mixing device. The ratio of materials fed in at the inlet will be substantially the ratio of materials in the mixture provided when the materials reach the output end.

Rotating mixing devices are not as efficient as they could be when the materials fed thereto themselves are not in the proper proportions. When an improper ratio of materials is supplied to a rotating mixer over short time intervals and the proper proportions are supplied thereafter the mixing time must be increased beyond the mixing time which may be employed when the proper proportions are fed continuously.

In certain mixing operations where the mixed materials chemically react over short time intervals, the longer time intervals for averaging input ratios may deleteriously affect the resultant product and the product may then have properties which make it unacceptable.

BRIEF DESCRIPTION OF THE INVENTION In accordance with this invention a method is provided for operating a mixer which includes the steps of combining first and second viscous materials into a combined stream of viscous material wherein measured amounts of the first and second viscous material flow, and applying the combined stream of viscous material to the mixer.

It has been found that the method is particularly suitable for use with a mixer employing no rotating parts and, particularly, when the first viscous material is surrounded in the combined stream by the second viscous material.

A mixer block is also provided for practicing the method of this invention. The mixer block includes a mixing chamber in the mixing block which is defined by an inner guiding wall. The mixing chamber terminates in an opening at an output end thereof. The mixer block has a first inlet for introducing the first viscous material into the mixing chamber located at a point in the mixing block displaced from the outlet end and a second inlet for introducing the second viscous material into the mixing chamber. The second inlet is located at a point in the mixing chamber between the first inlet and the outlet end.

DESCRIPTION OF THE FIGURES DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, we see a mixer block 10 having a mixer 11 employing no rotating parts connected to an outlet end 15 of the mixer block 10. The mixer block 10 together with the mixer 11 form a mixer unit which may be employed for mixing chemicals which react with each other. For example, in the embodiment shown the mixer unit formed by the mixer block 10 and the static mixer 11 are employed to.com- I bine a resin and catalyst which harden a predetermined time interval after mixing. It should be noted that mixing of this type presents problems which the mixing of inert materials does not present. For example, if the mixed material was allowed to remain in'either the mixing block 10 or mixer 11, it would harden thereby rendering the devices inoperable. Therefore, it should be noted that the cavity 31 (see FIG. 2) in the mixing block 10 provides a smooth path therethrough sothat no corners or crevices are provided for the resting of the mixed materials. This configuration is also particularly suitable for resin or solvent purging.

A quick disconnect clamp 13 secures an adapter pipe 14 to a first inlet 16 of the mixer block 10. An outlet 12 is positioned downstream from first inlet 16 substantially adjacent to outlet end 15-. The material introduced through first inlet 16 will flow to the outlet 12 through a cavity 31 (see FIG. 2) in the mixing block 10. The mixer 11 may be of the types shown or referred to in U.S. Pat. No. 3,286,992. It should be understood that any mixer can be employed with the mixing block and method of this invention and-that greatly improved performance has been achieved with mixers employing no rotating parts when used therewith.

Referring now to FIG. 2, we see a three-way valve 17 which may be actuated by a control member 18 to connect the first inlet 16 to either a source of resin through a pipe 19 or a source of solvent through a pipe 21. The control member 18 may also be positioned to prevent either the resin or solvent from entering the first inlet 16.

A second three-way valve 22 is connected to the mixing block 10 at a second inlet 23 by a check valve 24. It should be noted that the check valve 24 and the adapter pipe 14 each have an 0" ring 26 for normal sealing purposes. The three-way valve 22 is connected to a source of catalyst by a pipe 27 to an outlet pipe 28. The control member 29 of the valve 22 can connect the pipe 27 to the second inlet 23 to the ratio check tube 28. The control member 29 can also be positioned to isolate the pipe 27. I

It should be noted that the check valve 24 extends into the cavity 31 in the mixing block 10. The cavity 31 has a smooth inner guiding wall 32. The check valve 24 is adapted to introduce material approximately centrally of the interior of the cavity 31. In particular, check valve 24 comprises an "O" ring 20 which seals outlet openings (not shown) disposed in annular configuration. Material passes through check valve 24 when pressure is applied to the material forcing the O ring 20 from its sealing position to an extended open position. When the pressure is removed, ring 20 snaps back to its sealing position. This type of check valve has been found to be particularly advantageously employed when practicing the present invention because the resin or solvent purge has been found to effectively clean the check valve. In particular, when resin is employed, it does not harden within cavity 31. Further, the resin does not enter the check valve and harden therein.

When resin is being introduced into the cavity 31 through the three-way valve 17, it flows therefrom through the cavity to the outlet 12 and from there into the mixer 11. As noted, the check valve 24 introduces catalyst into the interior of the stream of resin produc ing a coaxial linear flow.

Referring now to FIG. 3, we see in particular the quick disconnect clamp 13 holding the adapter 14 against the mixing block 10. The tapered back end 34 thereof should be particularly noted which draws the clamp 13 against the adapter 14 as the wing nut 36 is tightened drawing the clamp 13 against the mixing block 10.

Mixer blocks normally employ a check valve at each inlet. In accordance with the present invention, the adapter 14, which is substantially an open pipe, may be, and preferably is, employed. This is possible because first inlet 16 is dispose upstream of second inlet 23 and the purging material, be it a solvent such as acetone or the resin itself, is introduced through the upstream inlet 16. Thus, the purging stream itself prevents catalyst from entering inelt 16 and the purging stream is more effective in that it is introduced directly and need not clean the check valve which would otherwise be employed and which would be difficult to clean since the purging material would be introduced through it and material may stick in back of it.

It should be noted that the size of the cavity 31 and the mass of the mixer block have been kept to a minimum. The fact that the size of the cavity 31 has been kept to a minimum insures that a minimal amount of material is wasted at the end of a cycle. This is particularly important where expensive materials are being used and cycles or runs are relatively short.

After a run is complete, the control member 18 on the three-way valve 17 is switched from a position which allows the resin to enter the cavity 31 to the position which allows the solvent from the pipe 21 to be forced through the cavity 31 and then the mixer 11. The control member 29 is placed in a neutral position so that the catalyst no longer is entering the chamber 31. In this way, solvent can immediately be sent through the system clearing out the mixer of resin and catalyst which would otherwise harden therein. It should be understood, of course, that by merely turning off the catalyst and continuing running resin through the system, a resin purge can be achieved.

It should be noted that provisions are made in the mixer block 10 (see FIG. I) for a thermistor 33 and a thermocouple 34 to be mounted therein. The thermistor 33 is employed in a control circuit (not shown) which regulates the temperature of the block 10. Since the mass of the block 10 is low, the temperature thereof can be controlled rapidly. This insures fast heat up and fast cool down for stable heat control when required. The thermocouple 34 may be connected to a pyrometer (not shown) for visual indications of the temperature of the block 10.

It should be understood that the present description has been by way of example only, it has not been intended as a limitation to the scope of the invention, and that while the invention has been disclosed with respect to a particular embodiment thereof, numerous others will become obvious to those of ordinary skill in the art in light hereof.

What is claimed is:

l. A mixer block for producing a stream of two or more viscous materials, comprising a mixing chamber in said mixing block, said mixing chamber being defined by an inner guiding wall in said block, said mixing chamber terminating in an opening at an outlet end;

first inlet means for introducing a stream ofa first viscous material into said mixing chamber, located at a point in said mixing block displaced from said outlet end;

second inlet means for introducing a second viscous material into said mixing chamber, said second inlet means being located at a point in said mixing chamber between said first inlet means and said outlet end, a portion of said second inlet means extending into said mixing chamber;

a check valve in communication with said portion of said second inlet means extending into said mixing chamber, said check valve extending into said mixing chamber and adapted to control the amount of and to introduce said second viscous material into the interior of said mixing chamber away from said guide wall thereof and into the interior of a stream of said first viscous material introduced via said first inlet means, thereby producing a coaxial linear flow of said first and second viscous materials.

2. In combination with the mixer block as defined in claim 1:

a mixer connected to said outlet end, said mixer employing no rotating parts.

3. In combination with a mixer block as defined in claim 1:

first means for supplying said first viscous material to said first inlet means so that said first viscous material tends to fill said mixing chamber and flow towards said outlet end;

second means for supplying said second viscous material to said second inlet means;

said mixer block being further characterized in that said second viscous material is introduced into the interior of said mixing chamber so as to be surrounded by the flow of said first viscous material.

4. The combination as defined in claim 3 in which said first inlet means introduces a greater quantity of said first viscous material into said mixing chamber than said second inlet means introduces of said second viscous material.

5. The combination as defined in claim 4 in which said first viscous material flows to said outlet end along a path unencumbered by blocking surfaces so that said mixing chamber can be purged of said first and second viscous materials.

6. The combination as defined in claim 4 in which said first inlet means comprises an open pipe and purging means for purging said mixing chamber are selectively connected to said open pipe for feeding of purging materials therethrough into said mixing chamber.

7. The combination as defined in claim 6 in which said open pipe terminates flush with said inner guiding wall.

8. The method as defined in claim 1 wherein said first viscous material is surrounded in said combined stream by said second viscous material.

9. A method of operating a mixer, which mixer employs no rotating parts, which comprises flowing a meaunder linear flow to said mixer. 

1. A mixer block for producing a stream of two or mOre viscous materials, comprising a mixing chamber in said mixing block, said mixing chamber being defined by an inner guiding wall in said block, said mixing chamber terminating in an opening at an outlet end; first inlet means for introducing a stream of a first viscous material into said mixing chamber, located at a point in said mixing block displaced from said outlet end; second inlet means for introducing a second viscous material into said mixing chamber, said second inlet means being located at a point in said mixing chamber between said first inlet means and said outlet end, a portion of said second inlet means extending into said mixing chamber; a check valve in communication with said portion of said second inlet means extending into said mixing chamber, said check valve extending into said mixing chamber and adapted to control the amount of and to introduce said second viscous material into the interior of said mixing chamber away from said guide wall thereof and into the interior of a stream of said first viscous material introduced via said first inlet means, thereby producing a coaxial linear flow of said first and second viscous materials.
 2. In combination with the mixer block as defined in claim 1: a mixer connected to said outlet end, said mixer employing no rotating parts.
 3. In combination with a mixer block as defined in claim 1: first means for supplying said first viscous material to said first inlet means so that said first viscous material tends to fill said mixing chamber and flow towards said outlet end; second means for supplying said second viscous material to said second inlet means; said mixer block being further characterized in that said second viscous material is introduced into the interior of said mixing chamber so as to be surrounded by the flow of said first viscous material.
 4. The combination as defined in claim 3 in which said first inlet means introduces a greater quantity of said first viscous material into said mixing chamber than said second inlet means introduces of said second viscous material.
 5. The combination as defined in claim 4 in which said first viscous material flows to said outlet end along a path unencumbered by blocking surfaces so that said mixing chamber can be purged of said first and second viscous materials.
 6. The combination as defined in claim 4 in which said first inlet means comprises an open pipe and purging means for purging said mixing chamber are selectively connected to said open pipe for feeding of purging materials therethrough into said mixing chamber.
 7. The combination as defined in claim 6 in which said open pipe terminates flush with said inner guiding wall.
 8. The method as defined in claim 1 wherein said first viscous material is surrounded in said combined stream by said second viscous material.
 9. A method of operating a mixer, which mixer employs no rotating parts, which comprises flowing a measured amount of a second viscous material into the interior of a stream of a measured amount of a first viscous material thereby establishing linear flow of said combined streams of first and second viscous materials; controlling the flow of said second viscous material into said stream of first viscous material, said control being effected immediately prior to the point at which said second viscous material flows into the interior of said first viscous material; and applying said combined stream of viscous material under linear flow to said mixer. 